1. Field of the Invention
The present invention relates to an exerciser and more particularly to an exerciser having a solid driving structure.
2. Description of the Prior Art
Typical exercisers, particularly the cycling exercisers comprise a pair of foot pedals coupled to a spindle with a sprocket-and-chain coupling mechanism or with a pulley-and-belt coupling device. The sprocket is normally rotatably secured to the hub of the cycle exerciser with a unidirectional bearing. However, the unidirectional bearing includes a relatively smaller outer diameter and will suffer a great transmission torque or force, such that the unidirectional bearing will normally be easily damaged after use.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional exercisers.
The primary objective of the present invention is to provide an exerciser including a solid driving structure for allowing the sprocket or the pulley to be solidly and effectively driven by the spindle via the unidirectional bearing.
In accordance with one aspect of the invention, there is provided an exerciser comprising a base including a hub provided therein, a spindle rotatably retained in the hub of the base, and including a peripheral plate extended radially outward therefrom, a rotary member rotatably engaged onto the spindle, a unidirectional driving device including a frame engaged between the peripheral plate and the rotary member, and a pair of cranks coupled to the spindle for driving the rotary member unidirectionally with the unidirectional driving device.
The rotary member includes a casing secured in a middle portion thereof and having an outer peripheral portion, the rotary member includes a peripheral flange extended therefrom for engaging with the outer peripheral portion of the casing and for solidly securing the casing to the rotary member.
The casing includes a plurality of axially extended extension extended from the outer peripheral portion thereof for solidly engaging into the rotary member.
The frame of the unidirectional driving device includes a bore formed therein for receiving the peripheral plate of the spindle, and at least one channel formed therein and communicating with the bore of the frame and having a shallower end and a deeper end, a roller received in the at least one channel of the frame, and a spring biased projection engaged in the frame and engaged with the roller for biasing the roller toward the shallower end of the at least one channel of the frame and for allowing the roller to be clamped between the frame and the peripheral plate of the spindle.
A wheel is further provided and rotatably secured to the base with a shaft, and means for coupling the rotary member to the wheel.
The coupling means includes a first pulley provided on the wheel, the rotary member is a second pulley, and a belt engaged over the first pulley and the second pulley for allowing the wheel to be rotated and driven by the second pulley.
A device is further provided for magnetically retarding the wheel to retard and brake the wheel.
Further objectives and advantages of the present invention will become apparent from a careful reading of a detailed description provided hereinbelow, with appropriate reference to accompanying drawings.